Alert archive / Minnesota / Special Weather Statements in 2018

Special Weather Statement, NWS Twin Cities, MN

September 20, 2018Hennepin County, Ramsey County, Minnesota

NWS Twin Cities, MN issued this special weather statement at Sep 20, 2018, 5:21 PM CDT for Hennepin County, Ramsey County, Minnesota. It was in force for 54 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Sep 20, 2018, 5:21 PM CDT (22:21 UTC)
Expired: Sep 20, 2018, 6:15 PM CDT
In force: 54 min
Issued by: NWS Twin Cities, MN

Counties Hennepin County, MN, Ramsey County, MN

The radar

The Minneapolis radar (KMPX), 19 km from the middle of the area, began a volume at 22:24 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 10.4 hours before the alert went out and 21 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 18 J/kg
Mixed-layer CIN: -80 J/kg
Mixed-layer LCL: 461 m above ground
0-6 km bulk shear: 48 kt
0-1 km storm-relative helicity: 195 m²/s²
0-3 km storm-relative helicity: 20 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

Open this sounding in Storm Lab

The text

As transmitted.

080 
WWUS83 KMPX 202221
SPSMPX

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE Twin Cities/Chanhassen MN
521 PM CDT THU SEP 20 2018
 
MNC019-053-123-202315-
Hennepin-Carver-Ramsey-
521 PM CDT THU SEP 20 2018

...URBAN AND SMALL STREAM FLOODING EXPECTED...

Thunderstorms with heavy rain will cause minor flooding in the
following counties...

Hennepin...Carver...Ramsey...

* Until 615 PM CDT.

* At 521 PM CDT, Doppler radar indicated heavy rain due to
  thunderstorms. This will cause urban and small stream flooding.
  Overflow of water will result in minor flooding of poor drainage
  locations in the area. Up to two inches of rain have already
  fallen.

* Some locations that will experience flooding include...
  Minneapolis, St. Paul, Bloomington, Brooklyn Park, Plymouth, Eden
  Prairie, Minnetonka, Edina, St. Louis Park, Maplewood, Roseville
  and Brooklyn Center.

Additional rainfall of around an inch is expected over the area 
through 6 PM. This additional rain will result in minor flooding.

This includes the following streams and drainages...Battle Creek...
Bass Creek...South Fork Ninemile Creek...Riley Creek...Ryan Creek...
Bevens Creek...Carver Creek...Bassett Creek...Minnehaha Creek...
Chaska Creek...Bluff Creek...Mississippi River...Ninemile Creek...
Minnesota River and Purgatory Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

&&

LAT...LON 4473 9379 4479 9381 4497 9358 4507 9339
      4510 9328 4504 9328 4504 9323 4511 9322
      4510 9300 4505 9298 4498 9299 4489 9332
      4482 9340 4480 9357

$$

The office that day

Everything else NWS Twin Cities, MN issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 20, 12:13 PM CDT	Special Weather Statement	MPX	Brown, Nicollet	32 min
Sep 20, 12:53 PM CDT	Special Weather Statement	MPX	Brown	37 min
Sep 20, 1:33 PM CDT	Special Weather Statement	MPX	Le Sueur, Scott	42 min
Sep 20, 1:49 PM CDT	Special Weather Statement	MPX	Dakota	26 min
Sep 20, 2:07 PM CDT	Special Weather Statement	MPX	Rice, Washington	38 min
Sep 20, 2:31 PM CDT	Special Weather Statement	MPX	Ramsey	119 min
Sep 20, 2:46 PM CDT	River Flood Warning	MPX	Redwood	9 days
Sep 20, 3:00 PM CDT	Special Weather Statement	MPX	Yellow Medicine	30 min
Sep 20, 3:24 PM CDT	Special Weather Statement	MPX	Renville	36 min
Sep 20, 4:50 PM CDT	Special Weather Statement	MPX	Ramsey	85 min
Sep 20, 5:30 PM CDT	Severe Thunderstorm Warning	MPX	Blue Earth, Faribault, Martin, Watonwan	45 min
Sep 20, 5:51 PM CDT	Special Weather Statement	MPX	Carver, Le Sueur, Nicollet, Sibley	24 min
Sep 20, 5:54 PM CDT	Areal Flood Warning	MPX	Anoka, Carver, Dakota, Hennepin, Ramsey, Scott and 2 more	3 hr
Sep 20, 5:59 PM CDT	Severe Thunderstorm Warning	MPX	Blue Earth, Faribault, Waseca	46 min
Sep 20, 6:13 PM CDT	Severe Thunderstorm Warning	MPX	Carver, Dakota, Hennepin, Ramsey, Scott	47 min
Sep 20, 6:15 PM CDT	Severe Thunderstorm Warning	MPX	Carver	15 min
Sep 20, 6:19 PM CDT	Tornado Warning	MPX	Le Sueur, Rice, Waseca	41 min
Sep 20, 6:23 PM CDT	Severe Thunderstorm Warning	MPX	Freeborn, Le Sueur, Rice, Steele, Waseca	52 min
Sep 20, 6:40 PM CDT	Tornado Warning	MPX	Goodhue, Rice, Steele	35 min
Sep 20, 6:41 PM CDT	Severe Thunderstorm Warning	MPX	Anoka, Dakota, Goodhue, Hennepin, Ramsey, Washington	34 min
Sep 20, 6:49 PM CDT	Tornado Warning Tornado observed	MPX	Dakota, Goodhue, Rice	41 min
Sep 20, 3:45 PM CDT	Special Weather Statement	MPX	Chippewa	45 min

Nearby

Special Weather Statements in Minnesota, 2018 Every special weather statement in 2018

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.